Association between the IL1B, IL1RN polymorphisms and COPD risk: a meta-analysis.

Xie ZK, Huang QP, Huang J, Xie ZF - Sci Rep (2014)

Bottom Line:
Odds ratio (OR) and 95% confidence interval (CI) were used to investigate the strength of the association.LL: OR = 3.16, 95% CI: 1.23-8.13, Pz = 0.017 and OR = 3.20, 95% CI: 1.13-9.12, Pz = 0.029, respectively).Further studies should be performed in other ethnic groups besides East Asians.

ABSTRACTThe interleukin-1 (IL-1) gene polymorphisms have been implicated in chronic obstructive pulmonary disease (COPD) risk, but results are controversial. We aimed to conduct a meta-analysis to address this issue. Odds ratio (OR) and 95% confidence interval (CI) were used to investigate the strength of the association. The meta-analysis revealed no association between the IL1B (-511), (-31), (+3954) polymorphisms and COPD risk. However, stratification by ethnicity indicated that the T allele carriers of the IL1B (-511) polymorphism and the C allele carriers of the IL1B (-31) variant were associated with an increased risk for developing COPD in East Asians (OR = 1.61, 95% CI: 1.13-2.31, Pz = 0.009 and OR = 1.55, 95% CI: 1.14-2.11, Pz = 0.006, respectively). The meta-analysis revealed a significant association between the IL1RN (VNTR) polymorphism and COPD risk in all study subjects and East Asians under homozygote model (22 vs. LL: OR = 3.16, 95% CI: 1.23-8.13, Pz = 0.017 and OR = 3.20, 95% CI: 1.13-9.12, Pz = 0.029, respectively). Our meta-analysis suggests that the IL1B (-511), (-31) and IL1RN (VNTR) polymorphisms are associated with COPD risk in East Asians. There is no association between the IL1B (+3954) polymorphism and COPD risk. Further studies should be performed in other ethnic groups besides East Asians.

Mentions:
Figure 1 showed the process of identifying eligible studies. 487 publications were identified from the initial keywords search. After review, 474 were excluded. Overall, 12 studies from 11 publications met our inclusion criteria with a total of 1530 COPD patients and 1524 controls1112131415161718192021. Table 1 summarized the characteristics of the studies included in the meta-analysis. In terms of ethnicity, eight studies including 1055 cases and 1199 controls were performed in East Asians1112141516171920, two studies containing 169 cases and 97 controls were undertaken in Arabians1221, one study with 102 cases and 20 controls was conducted in Europeans13, and one study including 204 cases and 208 controls was performed in South Asians18. The publication of Hegab et al. contained an Egyptian study and a Japanese study, respectively12. It was noteworthy that we did not extract data for the IL1B (−511), (−31) polymorphisms from the Liu et al. study17, since they further evaluated these two polymorphisms using larger sample numbers in another study19. In addition, the data for the IL1B (−31) SNP from the Liu et al. study19 and the data for the IL1RN (VNTR) polymorphism from the Hegab et al. study12, the Lee et al. study16, and the Shukla et al. study18 presented deviations from HWE in controls, respectively, so we did not include them in the final analysis.

Mentions:
Figure 1 showed the process of identifying eligible studies. 487 publications were identified from the initial keywords search. After review, 474 were excluded. Overall, 12 studies from 11 publications met our inclusion criteria with a total of 1530 COPD patients and 1524 controls1112131415161718192021. Table 1 summarized the characteristics of the studies included in the meta-analysis. In terms of ethnicity, eight studies including 1055 cases and 1199 controls were performed in East Asians1112141516171920, two studies containing 169 cases and 97 controls were undertaken in Arabians1221, one study with 102 cases and 20 controls was conducted in Europeans13, and one study including 204 cases and 208 controls was performed in South Asians18. The publication of Hegab et al. contained an Egyptian study and a Japanese study, respectively12. It was noteworthy that we did not extract data for the IL1B (−511), (−31) polymorphisms from the Liu et al. study17, since they further evaluated these two polymorphisms using larger sample numbers in another study19. In addition, the data for the IL1B (−31) SNP from the Liu et al. study19 and the data for the IL1RN (VNTR) polymorphism from the Hegab et al. study12, the Lee et al. study16, and the Shukla et al. study18 presented deviations from HWE in controls, respectively, so we did not include them in the final analysis.

Bottom Line:
Odds ratio (OR) and 95% confidence interval (CI) were used to investigate the strength of the association.LL: OR = 3.16, 95% CI: 1.23-8.13, Pz = 0.017 and OR = 3.20, 95% CI: 1.13-9.12, Pz = 0.029, respectively).Further studies should be performed in other ethnic groups besides East Asians.

ABSTRACTThe interleukin-1 (IL-1) gene polymorphisms have been implicated in chronic obstructive pulmonary disease (COPD) risk, but results are controversial. We aimed to conduct a meta-analysis to address this issue. Odds ratio (OR) and 95% confidence interval (CI) were used to investigate the strength of the association. The meta-analysis revealed no association between the IL1B (-511), (-31), (+3954) polymorphisms and COPD risk. However, stratification by ethnicity indicated that the T allele carriers of the IL1B (-511) polymorphism and the C allele carriers of the IL1B (-31) variant were associated with an increased risk for developing COPD in East Asians (OR = 1.61, 95% CI: 1.13-2.31, Pz = 0.009 and OR = 1.55, 95% CI: 1.14-2.11, Pz = 0.006, respectively). The meta-analysis revealed a significant association between the IL1RN (VNTR) polymorphism and COPD risk in all study subjects and East Asians under homozygote model (22 vs. LL: OR = 3.16, 95% CI: 1.23-8.13, Pz = 0.017 and OR = 3.20, 95% CI: 1.13-9.12, Pz = 0.029, respectively). Our meta-analysis suggests that the IL1B (-511), (-31) and IL1RN (VNTR) polymorphisms are associated with COPD risk in East Asians. There is no association between the IL1B (+3954) polymorphism and COPD risk. Further studies should be performed in other ethnic groups besides East Asians.